Clinical utility of anti-CCP assay in patients with rheumatoid arthritis

Abstract

Rheumatoid arthritis is a systemic autoimmune disease of unknown etiology. The major autoantibody detected in RA patients is rheumatoid factor. RF positivity is included in the American College of Rheumatology (ACR) classification criteria for the diagnosis of RA. RF assay is an easy, and convenient method. However, since RF is detected in only 50-80% of RA sera, and is frequently present in patients with other autoimmune disease and in the elderly healthy population, diagnosis of RA using RF assay remains suboptimal. Other autoantibodies detected in RA are anti RA33, anti-Sa, anti-p68, anti-calpastatin, AKA, and antiperinuclear factor, but these antoantibodies have demonstrated lower sensitivity for the diagnosis of RA (Choi et al., 2005). A new group of autoantibodies that has generated particular interest are the anti- cyclic citrullinated peptide antibodies, First described by Schellekens et al, 1998. This discovery led to the development of assays employing cyclic citrullinated peptides (CCP) to measure antibodies recognising citrullinated antigensas a diagnostic test for RA Further purification of the antigen led to the development of the second generation test, anti-CCP2, with better performance.

In this study, we aimed to evaluate the clinical utility of anti-CCP2 assay by ELISA method as a useful new serological test for the diagnosis of RA versus RF, and to correlate it with the disease activity parameters, functional disability, and radiological destruction.•

This study included 50 patients with rheumatoid arthritis diagnosed according to the American College of Rheumatology (ACR) 1987 revised criteria for the classification of rheumatoid arthritis, 37 patients with a variety of rheumatic diseases, and 10 healthy controls.

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